1. Field of the Invention
The present invention relates to a portable machine for cleaning planar surfaces, such as carpeted floors, upholstery, wall coverings and the like, and finds particular application in such machines where hot cleaning liquids are sprayed onto the surface and are then removed by suction.
2. Description of the Prior Art
Cleaning systems that circulate and spray liquids are widely used for cleaning carpets, upholstery, fabric and wall coverings, as well as for hard surfaces such as ceramics. Cleaning systems of this type which circulate and spray liquids often include a solution tank of liquid cleaning solution supported on a wheel mounted base or framework. The framework also supports a liquid pump for circulating the cleaning solution and one or more vacuum motors for recovering the solution and returning the used solution to a recovery tank. Many of these systems use a “cleaning head” which is part of a “cleaning wand” to spray liquid cleaning solution toward the surface being cleaned, for example, while the cleaning head is being pushed across the floor. In many such systems, the cleaning head is not integral with the base or framework, but rather is coupled to the solution tank through pliable hosing and the associated cleaning wand, which is thus is movable independently. On the return stroke across the floor, a vacuum source creates a high velocity airstream that draws the dispensed liquid from the surface being cleaned upwardly into an internal chamber of the cleaning head and through the pliable hosing to the recovery tank, thereby extracting soil, debris and other foreign matter to clean the surface. The spray operation of this type device is thus “on-and-off” in its nature.
A variety of devices of the above type are known in the relevant industries. For example, a commercially available line of carpet extractors of the above general type is sold as the “PFX1350 Series Extractors” byPowr-Flite®, a Tacony Company, 3101 Wichita Court, Fort Worth, Tex., 76140.
Alternatively, a surface cleaning apparatus can be self-contained, in the sense of providing a wheel supported housing that incorporates the necessary motors and contains the cleaning fluid, and further incorporates the cleaning tool head as a part of the same housing, for example, through a pair of pivot arms. In other words, the cleaning head is attached to the machine housing and rolls across the floor with the housing. These type machines are typically operated in a constantly “on” fashion. This type of cleaning apparatus is described in U.S. Pat. No. 5,432,975 (Hilmanowski), issued Jul. 18, 1995, and in any number of other references.
The aforementioned devices, whether of the hose and wand variety, or of the self-contained housing variety, all utilize vacuum motors to draw up the dispensed cleaning solution from the surface being cleaned so that the used cleaning solution can be returned to the solution recovery tank. The vacuum motors which are mounted on the wheel mounted base or framework are often electrically powered from AC current and generate a good deal of heat. As a result, the motors typically feature some sort of exhaust chamber or shroud and may feature an exhaust fan or other heat exhaust arrangement to distribute or remove the excess heat generated by the vacuum motors. For example, the previously mentioned PFX1350 Extractor may be equipped with a 115 VAC, 104 cfm, 2 stage vacuum motor, or with a 120 VAC 3 stage vacuum motor. The heat generated by these motors has, in the past, been simply exhausted and in a sense wasted.
Heated cleaning solutions generally clean more effectively than unheated solutions. As a result, certain of the prior art portable machines have included heating components for the cleaning solution which is subsequently sprayed onto the surface to be cleaned and then suctioned back into a recovery tank. Many of these devices have utilized an electrical heater to heat the fluid to be applied to a given temperature before it is applied to the surface which is to be cleaned.
While carpet extractors utilizing axillary heating devices have been known and used successfully for a number of years, there are various shortcomings attendant with these prior art assemblies. As a general matter, the prior art devices utilizing electric solution heaters have required increased AC electrical power in order to sufficiently heat the fluids which are to be applied over the amount of power required to simply apply and extract a cold cleaning solution. Because the available electrical outlet capability is necessarily limited in typical residential and commercial buildings in North America, compromises in temperature rise and/or fluid flow rate must necessarily be made. Sometimes, the increased amperage being drawn has caused the operator to blow electrical fuses in the structure being cleaned. In many cases, it is also not generally practical to utilize multiple electrical cords running to the extractor unit. As a result, one smaller cord may overheat due to the increased electrical load.
To address this perceived shortcoming, various cleaning devices and machines have been introduced and which include self contained power supplies. These devices typically consist of multiple lead-acid batteries which are utilized to supply power to the cleaning device so it may operate remotely relative to an AC power source. While cleaning devices having self contained power sources have operated with some degree of success, the useful operational time of such devices is quite limited. Consequently, an operator must periodically stop these prior art machines either to recharge the batteries utilized with same; or in the alternative, remove the discharged batteries, and replace them with a fully charged set of batteries, so that the machine can continue in operation. Still further, machines of this type which have rechargeable batteries are also relatively large and heavy, and can be difficult to maneuver in small spaces.
A need exists, therefore, for a portable carpet extractor type machine which more effectively utilizes the excess heat generated by the vacuum motor or motors, rather than simply exhausting the excess heat.
A need also exists for such a portable carpet extractor device equipped with a solution heater which would actually allow the vacuum motors to run cooler, while at the same time supplying heated cleaning solution for more efficient cleaning.
A need also exists for such an improved carpet extractor which either eliminates the need for a separate electric solution heater, or which acts to supplement the solution heating process so that less power is required for the electric heater where such a heater is present.
A need exists for such a device which would provide adequate heat to break down grease and enhance the cleaning process without requiring additional power cords or power consumption and which would not risk damage to the carpet being cleaned.
A need also exists for such a device which would maintain its heat over an extended period of time, which would be simple and dependable in operation and which would not add significantly to the overall cost of the extractor device.